OPTICAL PROBING OF INTERFACE ROUGHNESS IN RESONANT-TUNNELING STRUCTURES

We report on photoluminescence (PL) and photoluminescence-excitation m easurements in GaAs/In0.1Ga0.9As/AlAs double-barrier tunneling structu res as a function of bias voltage and temperature. We have observed a splitting in the quantum well photoluminescence due to island formatio n in the quantum well. We have a good correlation between the variatio n of integrated PL intensity, linewidth, and tunnel current bias for b oth lines. The temperature dependence of photoluminescence spectra sho ws that transfer of carrier between islands can be tuned by the applie d bias and that states in different islands are populated by electrons in the resonant tunneling process. (C) 1997 American Institute of Phy sics.